This invention relates to the preparation of poultry carcasses for human consumption, and more particularly, the invention relates to the stage of poultry processing after which the vent of a bird has been cut from the body to form an opening in the bird, whereupon a knife is thrust into the cut made about the vent and is moved so as to cut through the bird and enlarge the opening into the body cavity of the bird.
In the modern processing of poultry, it has become common practice to hang the birds by their feet or ankle joints from an elevated or "overhead" conveyor system and to move the birds through various processing steps in the poultry processing plant. After the birds have been defeathered, it is desirable to from a cut about the vent opening of the bird of a relatively small dimension so that the "plug" of material removed from the bird contains only a minimal amount of edible meat. After this initial cut has been made, it is necessary thereafter to enlarge this similar cut into a larger entryway into the cavity of the bird because the dimensions of the smaller cut are too limited to permit the entry of a tool into the body cavity for the purpose of removing the viscera within the cavity.
It has become common practice to move the birds to an "opener" machine which inserts a cutting element into the small, previously cut opening and which functions to cut through the body of the bird to enlarge the access opening into the body cavity of the bird. For example, U.S. Pat. Nos. 4,059,868, 4,136,421 and 4,257,142 all illustrate equipment for this purpose.
The prior art bird openers are somwhat complex in their construction and comprise a number of moving parts. The more parts and the more movement of the parts contributes to the possible malfunction of such a machine. Since birds that are to be opened by such a machine vary in size and shape, it is necessary to accurately position each bird with respect to the equipment so as to properly position the cutting blade of the equipment, and then to securely hold the bird as the cut is being made. Preferably, the cutting element is of small size so as to gain easy access in the relatively small, previously cut opening of the bird, and the apparatus functions to seize and hold and then to release each bird in the proper position and attitude. This avoids having the cutting element puncture or otherwise damage the organs of the bird which are adjacent the portion of the body that is to be cut.